Pancreatic Cancer-Derived Small Extracellular Vesicles Remodel Hepatic Pre-Metastatic Niche via Hybrid Epithelial–Mesenchymal States

Pancreatic ductal adenocarcinoma frequently metastasises to the liver, although the mechanisms underlying hepatic pre-metastatic niche formation remain unclear. Small extracellular vesicles mediate tumour–host communication and may drive hepatic microenvironment reprogramming. This study investigated the effects of pancreatic ductal adenocarcinoma-derived small extracellular vesicles on extracellular matrix remodelling and epithelial–mesenchymal transition-related plasticity in hepatic cells. Small extracellular vesicles were isolated from pancreatic ductal adenocarcinoma cell lines (MIAPaCa-2, PANC-1) and from the serum of 25 patients, characterized, and administered to hepatic stellate (LX-2) and hepatocyte-like (HEPA-RG) cells. Cell viability and migration were evaluated by functional assays, morphology by scanning electron microscopy, and molecular changes by RT-PCR, Western blotting, and immunofluorescence. In LX-2 cells, small extracellular vesicles exposure increased metabolic activity, adhesion, and migration, while inducing morphological and molecular changes associated with extracellular matrix remodelling, including reduced collagen type I alpha 2 chain, vimentin, and E-cadherin expression. In HEPA-RG cells, viability was minimally affected, whereas migration and EMT-related plasticity were enhanced. Patient-derived small extracellular vesicles induced similar but less pronounced effects. Overall, pancreatic ductal adenocarcinoma-derived small extracellular vesicles induced early hepatic microenvironmental remodelling, supporting a potential role for tumour–liver crosstalk in pre-metastatic niche-associated processes, highlighting tumour–liver crosstalk as a potential therapeutic target.